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        <p>Library Version 11.2.5.3</p>
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          <th colspan="3" align="center">DB_ENV-&gt;repmgr_msg_dispatch()</th>
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          <th width="60%" align="center">Chapter 10. 
                Replication Methods
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    <div class="sect1" lang="en" xml:lang="en">
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            <h2 class="title" style="clear: both"><a id="repmgr_msg_dispatch"></a>DB_ENV-&gt;repmgr_msg_dispatch()</h2>
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      <pre class="programlisting">#include &lt;db.h&gt;

int
DB_ENV-&gt;repmgr_msg_dispatch(DB_ENV *env, 
        void (*msg_dispatch_fcn) (DB_ENV *env, DB_CHANNEL *channel, 
                                  DBT *request, u_int32_t nrequest,
                                  u_int32_t cb_flags), 
        u_int32_t flags);  </pre>
      <p>
        Sets the message dispatch function. This function is responsible
        for receiving messages sent from remote sites using either the
        <a class="xref" href="dbchannel_send_msg.html" title="DB_CHANNEL-&gt;send_msg()">DB_CHANNEL-&gt;send_msg()</a>
        or
        <a class="xref" href="dbchannel_send_request.html" title="DB_CHANNEL-&gt;send_request()">DB_CHANNEL-&gt;send_request()</a>
        methods. If the message received by this function was sent using the
        <a class="xref" href="dbchannel_send_msg.html" title="DB_CHANNEL-&gt;send_msg()">DB_CHANNEL-&gt;send_msg()</a>
        method then no response is required. If the message was sent using the
        <a class="xref" href="dbchannel_send_request.html" title="DB_CHANNEL-&gt;send_request()">DB_CHANNEL-&gt;send_request()</a>
        method, then this function must send a response using the 
        <a class="xref" href="dbchannel_send_msg.html" title="DB_CHANNEL-&gt;send_msg()">DB_CHANNEL-&gt;send_msg()</a>
        method.
    </p>
      <p>
         For best results, the
         <code class="methodname">DB_ENV-&gt;repmgr_msg_dispatch()</code> method should
         be called before the Replication Manager has been started.
    </p>
      <p>
         The <code class="methodname">DB_ENV-&gt;repmgr_msg_dispatch()</code> <span>
            <span>
                  method returns a non-zero error value on failure and 0 on success.
            </span>
            
        </span>
    </p>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp54386960"></a>Parameters</h3>
            </div>
          </div>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp54386312"></a>msg_dispatch_fcn</h4>
              </div>
            </div>
          </div>
          <p>
                 This parameter is the application-specific function used
                 to handle messages sent over Replication Manager message
                 channels. It takes four parameters:
             </p>
          <div class="itemizedlist">
            <ul type="disc">
              <li>
                <p>
                         <code class="literal">channel</code>
                     </p>
                <p>
                         Provides the DB_CHANNEL to be used to send
                         a response back to the originator of the message.
                         If the message was sent by the remote site using 
                         <a class="xref" href="dbchannel_send_request.html" title="DB_CHANNEL-&gt;send_request()">DB_CHANNEL-&gt;send_request()</a>
                         then this function should send a response back to
                         the originator using the channel provided on this
                         parameter. The message should be sent by calling 
                         <a class="xref" href="dbchannel_send_msg.html" title="DB_CHANNEL-&gt;send_msg()">DB_CHANNEL-&gt;send_msg()</a>
                         exactly once. 
                     </p>
                <p>
                         This channel is valid only during the current
                         invocation of the dispatch function; it is
                         destroyed when the dispatch function returns. The
                         application may not save a copy of the pointer and
                         use it later elsewhere. Methods that do not make
                         sense in the context of a message dispatch
                         function (such as 
                         <a class="xref" href="dbchannel_send_request.html" title="DB_CHANNEL-&gt;send_request()">DB_CHANNEL-&gt;send_request()</a>
                         and
                         <a class="xref" href="dbchannel_close.html" title="DB_CHANNEL-&gt;close()">DB_CHANNEL-&gt;close()</a>)
                         will be rejected with <code class="literal">EINVAL</code>.
                     </p>
              </li>
              <li>
                <p>
                         <code class="literal">request</code>
                     </p>
                <p>
                         Array of DBTs containing the message
                         received from the remote site.
                     </p>
              </li>
              <li>
                <p>
                         <code class="literal">nrequest</code>
                     </p>
                <p>
                         Specifies the number of elements in the
                         <code class="literal">request</code> array.
                     </p>
              </li>
              <li>
                <p>
                         <code class="literal">cb_flags</code>
                     </p>
                <p>
                         This flag is
                         <code class="literal">DB_REPMGR_NEED_RESPONSE</code> if the
                         message requires a response. Otherwise, it is
                         <code class="literal">0</code>.
                     </p>
              </li>
            </ul>
          </div>
          <p>
                 This function does not return a value. If the function
                 encounters an error, you can reflect the error back to
                 the originator of the message by formatting an error
                 message of your own design into the response.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp54398704"></a>flags</h4>
              </div>
            </div>
          </div>
          <p>
                  This parameter is currently unused, and must be
                  set to 0.
             </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp54393096"></a>Errors</h3>
            </div>
          </div>
        </div>
        <p>
            The <code class="methodname">DB_ENV-&gt;repmgr_msg_dispatch()</code>
            <span>
            <span>
                 method may fail and return one of the following non-zero errors:
            </span>
            
        </span>
        </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp54403584"></a>EINVAL</h4>
              </div>
            </div>
          </div>
          <p>
                If this method is called from a Base API application, 
                or if an invalid flag value or parameter was specified.
            </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp54402504"></a>Class</h3>
            </div>
          </div>
        </div>
        <p>
            <a class="link" href="env.html" title="Chapter 5.  The DB_ENV Handle">DB_ENV</a>  
        </p>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp54399352"></a>See Also</h3>
            </div>
          </div>
        </div>
        <p>
             <a class="xref" href="rep.html#replist" title="Replication and Related Methods">Replication and Related Methods</a> 
        </p>
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